Honeybees don't keep datebooks, and they don't just show up at the apple orchard, on schedule, to pollinate your trees. No, you have to rent them -- and thanks to the national decline in the number of healthy bees, the rental cost is on the rise.

A hive that cost $25 a few years ago now costs $75.

It's not his biggest expense, "but it's getting right up there," said Dan Boyer, owner of Ridgetop Orchards near Bedford. Pollination of a large orchard might require a shipment of 300 colonies. What once cost $7,500 is now $22,500.

Some growers are forgoing bee rentals, opting for "natural" pollination instead. Others simply aren't planting as much.

Planting less isn't an option for Mr. Boyer, because trees are planted years in advance, so he's cutting back on bees to save money -- instead of renting 300 hives, he rented 230 this year to pollinate his apple orchards.

He rents from commercial beekeeper Dave Hackenburg, of Buffy Bee Honey Farm near Lewisburg. The rule of supply and demand is buffeted by the rising cost of fuel (hives are delivered by the truckload) and the increase in sugar feed prices (up 50 percent since 2007).

"Our operating costs have gone sky-high in the last two years," Mr. Hackenburg said.

Same goes for other farmers -- corn, fertilizer and fuel costs are all up this year. But cost of bees is often overlooked because not every crop requires them. Apples? Yes. Peaches? No. Pumpkins? Yes. Corn? No. Cherries? Blueberries? Yes and yes.

Different fruits and vegetables flower in different seasons. Spring rentals -- to pollinate apple trees, for example -- might run $75 for a colony of 2,000 bees. But that same colony will cost $95 in the summer, to pollinate pumpkins or blueberry shrubs.

The dearth of bees is so bad that Congress is has convened two hearings on the subject, most recently on Thursday. Bee experts told the House horticulture and organic agriculture subcommittee that a record 36 percent of commercial bee colonies have been lost this year.

President Bush has authorized $20 million in funding for bee-related studies, and private companies are pitching in, too. California's Haagen-Dazs ice cream is pledging $250,000 for bee research at the University of California at Davis and Penn State, since so many of its ingredients, such as cherries, strawberries and almonds, rely on honeybee pollination.